Piston skirt expander



Dec. 3, 1935. SQLENBERGER' 2,023,035

PISTON SKIRT EXPANDER Filed Feb. 20, 1933 2 Sheets-Sheet 1 I860? M 3 2627567 er Dec. 3, 1935. D. M. VSOLENBERG'ER PISTON SKIRT EXPANDER Filed Feb. 20, 1953 2 Sheets-Sheet 2 3mm flea)? fl- Sodenberyer Wm M Patented Dec. 3, 1935 UNTED sr'rss ATENT oFFics,

Application February 20, 1933, Serial No. 657,716

5 Claims.

The invention relates to expanding devices for piston skirts and has for its object First, to obtain at construction which can be easily and quickly applied to any construction of piston where it is desired to expand or enlarge the diameter of the skirt portion thereof;

Second, to provide for secure attachment to the piston so that it will not be dislodged when the engine is in operation;

Third, to obtain an exceedingly simple and inexpensive construction to manufacture, and

Fourth, to limit the weight so as to not materially add to inertial force when the engine is running at high speed. With these and other objects in view the invention consists in the construction as hereinafter set forth.

In the drawings:

Fig. 1 is a side elevation of the piston showing my improved expander applied to the skirt thereof;

Fig. 2 is a horizontal section;

Fig. 3 is a view similar to Fig. 2 showing a modified construction;

Fig. 4. is a perspective view of the adjustment means.

Figs. 5, 6, 7, 8, 9, and 10 are views similar to Fig. 2 showing modified constructions;

Fig. 10a is a cross section substantially on line lt l of Fig. 10.

Fig. 11 is a side elevation of the nut, and

Fig. 12 is a bottom plan view thereof.

In the present state of. the art various devices have been employed for expanding piston skirts which may be generally classified as, first, normally rigid expanders; second, resilient expanders. With both types it is necessary to provide means for securely fastening the expander to the skirt which in many instances requires either a special construction of skirt or the machining of the same to provide some groove or recess with which the expander may be engaged. With my improved construction the expander is secured to the skirt by a fastener engaging an aperture in the skirt and itself held in place by the pressure of the expander. Preferably one or more holes are drilled radially through the skirt at the proper location and pins engaging these holes embrace the expander to hold the same from displacement.

For simplicity in construction, the expander is formed of a resilient wire or ribbon extending around the inside of the skirt. The fasteners may be variously constructed and secured to this ribbon but in each case the resilient pressure of the expander will hold the fastener in engagement has a reduced end portion C for fitting the bore B and a shoulder C for bearing against the inner face of the skirt. It is also provided with a bore or recess C adjacent to this shoulder for receiving one end of the wire A and with a second bore C spaced radially inward from the first bore for 15 the passage of the other end portion of the Wire A. The latter portion of the wire A is threaded by a nut E for bearing against one side of the post C. The nut is also provided with grooves E on its inner face which will engage with the 0 rounded cross section of the post and will normally lock the nut from turning. The post D is merely provided with a bore through which the wire A loosely passes and serves to support the same.

With the construction as described, to install the expander upon a piston the bores B and B are made through the skirt near the lower edge thereof and preferably upon diametrically opposite sides. slot F is cut therein at a point preferably midway between said bores B and B. The nut E is then adjusted on the threaded portion A so that the wire A may be contracted in diameter sufii- If the skirt is not already slotted, a 39 ciently to introduce it within the skirt .and to enor lesser extent to the inner surface of the skirt.

However, as this wire is resilient it will produce a yielding pressure instead of forming a rigid reinforcement. In each position of adjustment of the nut E the groove E therein will engage with the rounded post so as to lock the nut from accidentally loosening, and as there are a number of radial grooves in the nut, a fine adjustment can be made.

In operation, the expander when once adjusted will retain this adjustment and during the reciprocation of the piston it will be securely held from disengagement by the posts C and E. The entire mass of the structure is so small that even in high speed operation it will not materially add to the inertial forces.

With the modified construction shown in Fig. 3 in place of using a round wire, a ribbon G is employed, the construction being otherwise substantially the same.

In the modified construction shown in Fig. 5, H is a resilient split band or ring which is unprovided with any adjustment means but which is secured to the skirt by posts I. Fig. 6 shows a construction similar to Fig. 2 with the expander supported by three pins or posts I, J, J Also the threaded portion of the expander is curved at K which maintains the plane of the nut substantially parallel to the axis of the post for better locking engagement therewith. Fig. 7 shows a construction where a ribbon L is used for theexpander instead of a round wire. One end of this ribbon is secured in a slot in the head M of a screw M while the opposite end is secured to the post N. The nut E engages the screw and post the same as in Fig. 2. Fig. 8 shows a construction in which the expander O is provided with a series of loops 0' distributed around its circumference to increase the resiliency thereof. The ends of the expander are turned radially inward and are adjustably connected by a screw P and nut E. Fig. 9 shows a construction where the expander Q extends only half way around the skirt and is secured at its opposite ends to pins or posts R. One end is threaded at Q to engage the adjustable nut E. Figs. 10 and 10a. show a construction where the pin or post R instead of being apertured for the passage of the expander A is forked to embrace the expander and is held in engagement with the aperture in the skirt by the resiliency of the expander. With all of these modified constructions, an arcuate expander extends part way around the skirt and is heldfrom displacement by separate pins or posts engaging apertures in the skirt and themselves'held m position by the expander.

What I claim as my invention is:

1. A piston skirt expander comprising a substantially circular member, a pin or post for engaging a radial bore in a piston skirt and extending inward therefrom, one end of said circular member being attached to said post and the other end passing through a bore in said post, and a nut having a threaded engagement with the end portion of said member passing through said post forming an adjustable abutment against said post for expanding the diameter of said circular member.

2. A piston skirt expander comprising a band for extending around the inner face of a piston skirt, a shouldered pin or post for engaging a radia1 bore in said skirt to project inward therefrom, said post being attached to one end of said band at a point adjacent to said skirt, and being also provided with a bore or eyelet radially inward from said point of attachment for the passage of the opposite end portion of said band, the said opposite end portion being threaded, and a nut engaging the threaded portion of said band forming an adjustable abutment against said post and grooved on its inner face for interlocking with said post.

3. A piston skirt expander comprising a wire for extending around the inner face of a piston skirt with overlapping ends, one end portion being threaded, a shouldered post for engaging a radial bore in the skirt, said post having a socket for receiving one end of said wire and a bore radially inwardly displaced from said socket for the passage of the threaded portion, a nut engaging said threaded portion forming an adjustable abutment against said post, and a second pin slidably engaging said wire and adapted to engage a radial bore on the opposite side of the piston skirt.

4. A piston skirt expander comprising a substantially circular member, a pin or post for engaging an aperture in a piston skirt and extending inward therefrom, one end of said circular member being attached to said post and the opposite end of said member extending through an aperture in said post, the latter end portion being of arcuate form and threaded, and a nut engaging said threaded portion forming an adjustable abutment against said post for expanding the diameter of said circular member.

5. A piston skirt expander comprising a substantially circular member, a pin or post for engaging an aperture in a piston skirt and extending inward therefrom, one end of said circular member being attached to said post and the 0pposite end passing through a bore therein, a nut having a threaded engagement with the end portion of said member passing through said post and forming an adjustable abutment against the post for expanding the diameter of said circular member, said nut being provided with radially extending grooves therein for embracing the curved cross section of said post and interlocking therewith to hold against accidental displacement.

DEAN M. SOLENBERGER. 

